[v2,0/3] fetch the alignment of device dax

Message

Liu, Jingqi April 15, 2020, 3:35 a.m. UTC

This series adds libdaxctl support and fetchs the alignment of
device dax through libdaxctl [1] APIs.

QEMU uses mmap(2) to maps vNVDIMM backends and aligns the mapping
address to the page size (getpagesize(2)) by default. However, some
types of backends may require an alignment different than the page
size. The 'align' option is provided to memory-backend-file to allow
users to specify the proper alignment.

For device dax (e.g., /dev/dax0.0), the 'align' option needs to
match the alignment requirement of the device dax, which can be fetched
through the libdaxctl APIs.

[1] Libdaxctl is a part of ndctl project.
The project's repository is: https://github.com/pmem/ndctl

Changelog:
  v2: Per Paolo and Dan suggestions, fetch the alignment of device dax
      through libdaxctl APIs.

  v1: The initial version.
      Fetch the alignment through "/sys/dev/char/%d:%d/device/align".

Jingqi Liu (3):
  exec: fetch the alignment of Linux devdax pmem character device nodes
  docs/nvdimm: add description of alignment requirement of device dax
  configure: add libdaxctl support

 configure       | 30 +++++++++++++++++++++++++++
 docs/nvdimm.txt |  9 +++++++++
 exec.c          | 54 ++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 92 insertions(+), 1 deletion(-)

Comments

Liu, Jingqi April 19, 2020, 1:48 p.m. UTC | #1

Ping for comments.

Hi Paolo, Dan, Joao,
Any comments for this series.

Thanks,
Jingqi

On 4/15/2020 11:35 AM, Liu, Jingqi wrote:
> This series adds libdaxctl support and fetchs the alignment of
> device dax through libdaxctl [1] APIs.
>
> QEMU uses mmap(2) to maps vNVDIMM backends and aligns the mapping
> address to the page size (getpagesize(2)) by default. However, some
> types of backends may require an alignment different than the page
> size. The 'align' option is provided to memory-backend-file to allow
> users to specify the proper alignment.
>
> For device dax (e.g., /dev/dax0.0), the 'align' option needs to
> match the alignment requirement of the device dax, which can be fetched
> through the libdaxctl APIs.
>
> [1] Libdaxctl is a part of ndctl project.
> The project's repository is: https://github.com/pmem/ndctl
>
> Changelog:
>    v2: Per Paolo and Dan suggestions, fetch the alignment of device dax
>        through libdaxctl APIs.
>
>    v1: The initial version.
>        Fetch the alignment through "/sys/dev/char/%d:%d/device/align".
>
> Jingqi Liu (3):
>    exec: fetch the alignment of Linux devdax pmem character device nodes
>    docs/nvdimm: add description of alignment requirement of device dax
>    configure: add libdaxctl support
>
>   configure       | 30 +++++++++++++++++++++++++++
>   docs/nvdimm.txt |  9 +++++++++
>   exec.c          | 54 ++++++++++++++++++++++++++++++++++++++++++++++++-
>   3 files changed, 92 insertions(+), 1 deletion(-)
>